Receive a free burger (up to $10 value) with the purchase of an adult entree. In order to redeem the coupon, customers must be signed up for the restaurant's SoConnected email club. You also get a free and appetizer when you join!

Delta will serve Shake Shack burgers aboard select flights from JFK to LAX on Sunday. In addition, customers on the flights will receive a voucher for a free ShackBurger at the LA West Hollywood Shake Shack.